Don’t use Buffer.byteLength() as Deno can’t use it (#4324)

* Don’t use Buffer.byteLength() as Deno can’t use it

* Add changeset

* Add tests for Markdown & MDX with Deno

Co-authored-by: Matthew Phillips <matthew@skypack.dev>

.changeset/green-schools-pump.md

@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Use TextEncoder instead of Buffer.byteLength() for Deno compatibility

packages/astro/src/runtime/server/render/page.ts

@@ -49,10 +49,11 @@ export async function renderPage(
 			}
 			html += rest;
 		}
-		return new Response(html, {
+		const bytes = encoder.encode(html);
+		return new Response(bytes, {
 			headers: new Headers([
 				['Content-Type', 'text/html; charset=utf-8'],
-				['Content-Length', Buffer.byteLength(html, 'utf-8').toString()],
+				['Content-Length', bytes.byteLength.toString()],
 			]),
 		});
 	}

packages/integrations/deno/test/basics.test.js

@@ -59,3 +59,31 @@ Deno.test({
 		});
 	},
 });
+
+Deno.test({
+	name: 'Works with Markdown',
+	async fn() {
+		await startApp(async () => {
+			const resp = await fetch('http://127.0.0.1:8085/markdown');
+			const html = await resp.text();
+
+			const doc = new DOMParser().parseFromString(html, `text/html`);
+			const h1 = doc.querySelector('h1');
+			assertEquals(h1.innerText, 'Heading from Markdown');
+		});
+	},
+});
+
+Deno.test({
+	name: 'Works with MDX',
+	async fn() {
+		await startApp(async () => {
+			const resp = await fetch('http://127.0.0.1:8085/mdx');
+			const html = await resp.text();
+
+			const doc = new DOMParser().parseFromString(html, `text/html`);
+			const h1 = doc.querySelector('h1');
+			assertEquals(h1.innerText, 'Heading from MDX');
+		});
+	},
+});

packages/integrations/deno/test/fixtures/basics/astro.config.mjs

@@ -1,9 +1,10 @@
 import { defineConfig } from 'astro/config';
 import deno from '@astrojs/deno';
 import react from '@astrojs/react';
+import mdx from '@astrojs/mdx';
 
 export default defineConfig({
 	adapter: deno(),
-	integrations: [react()],
+	integrations: [react(), mdx()],
 	output: 'server',
 })

packages/integrations/deno/test/fixtures/basics/package.json

@@ -6,6 +6,7 @@
     "astro": "workspace:*",
     "@astrojs/deno": "workspace:*",
     "@astrojs/react": "workspace:*",
+    "@astrojs/mdx": "workspace:*",
     "react": "^18.1.0",
     "react-dom": "^18.1.0"
   }

packages/integrations/deno/test/fixtures/basics/src/pages/markdown.md

@@ -0,0 +1,6 @@
+---
+title: Title
+description: Description
+---
+
+# Heading from Markdown

packages/integrations/deno/test/fixtures/basics/src/pages/mdx.mdx

@@ -0,0 +1,6 @@
+---
+title: Title
+description: Description
+---
+
+# Heading from MDX